Silicone hydrogels formed from zero diluent reactive mixtures

ABSTRACT

The present invention relates to silicone hydrogels having a desirable balance of properties which can be formed without diluents. The silicone hydrogels are formed from reactive mixtures comprising at least one hydroxyl substituted, monofunctional polydialkylsiloxane monomer having between 2 and 120 dialkylsiloxane repeating units, at least one slow reacting hydrophilic monomer and at least one hydroxyl containing hydrophilic monomer.

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationNo. 61/579,690, filed on Dec. 23, 2011 entitled SILICONE HYDROGELSFORMED FROM ZERO DILUENT REACTIVE MIXTURES, and U.S. Provisional PatentApplication No. 61/579,683, filed on Dec. 23, 2011 entitled SILICONEHYDROGELS HAVING A STRUCTURE FORMED VIA CONTROLLED REACTION KINETICS,the contents of which are incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to silicone hydrogels having a desirablebalance of properties which can be formed without diluents.

BACKGROUND OF THE INVENTION

Soft contact lenses made from silicone hydrogels contact lenses offerimproved oxygen permeability as compared to soft lenses made fromnon-silicone materials such as poly(2-hydroxyethyl methacrylate) (HEMA).Initial efforts to make silicone hydrogel contact lenses were hamperedby the poor wettability, high modulus, poor clarity, hydrolyticinstability or the high cost of raw materials used to make many of thesesilicone hydrogels. While various solutions have proven somewhatsuccessful for each of these deficiencies, there remains a need forsilicone hydrogels that can be made from inexpensive commerciallyavailable monomers, and which have excellent wettability (without theneed for surface modification), low modulus, good clarity, and desirableoxygen permeability.

Silicone hydrogels formulations containing polymeric wetting agents,such as poly(N-vinylpyrrolidone) (PVP) and acyclic polyamides have beendisclosed. However, these polymers are quite large and require the useof special compatibilizing components, which need to be custommanufactured. Examples of compatibilizing components include 2-propenoicacid, 2-methyl-,2-hydroxy-3-[3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]disiloxanyl]propoxy]propylester (SiGMA).

Monomeric N-vinylpyrrolidone (NVP) has also been incorporated intomonomer mixes used to make a silicone hydrogel polymer, typically inamounts of about 25-55% (by weight) of the monomer mix. Such materialshave been described in U.S. Pat. Nos. 4,136,250; 4,153,641; 4,260,725and 6,867,245. The materials described in these references generallyincorporate polyfunctional silicone monomers or macromers, that act ascrosslinking agents, and thereby increase the modulus of the finalpolymer.

U.S. Pat. No. 4,139,513 discloses that 2-propenoic acid, 2-methyl-,2-hydroxy-3-[3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]disiloxanyl]propoxy]propylester (SiGMA) can be used to form lenses from formulations comprisingNVP and HEMA. SiGMA is the only source of silicone disclosed. However,because of the relatively low silicone content in those monomers,desirable levels of oxygen permeability in the final polymers aredifficult to achieve.

US 2010/0048847 discloses silicone hydrogels made from a blend of amonomethacryloxyalkyl polydimethylsiloxane methacrylate with about 52%NVP, HEMA and TRIS. Diluents were disclosed to be necessary, and evenusing a blend of ethanol and ethyl acetate as a diluent, the polymersdisclosed were (to varying degrees) hazy. Haziness was reduced by theaddition of at least about 1.5% methacrylic acid (MAA).

Addition of anionic monomers such as MAA can, however, cause hydrolyticinstability in silicone hydrogels, as was disclosed in “The role ofionic hydrophilic monomers in silicone hydrogels for contact lensapplication”, Lai, Y., Valint, P., and Friends, G.; 213^(th) ACSNational Meeting, San Francisco, Apr. 13-17, 1997.

SUMMARY OF THE INVENTION

The present invention relates to a silicone hydrogel comprising,consisting and in some embodiments consisting essentially of

about 8 to about 17 wt % silicon, an advancing contact angle of lessthan about 80° without surface modification formed from a reactivemixture comprising, consisting of, or consisting essentially of

at least one monofunctional polydialkylsiloxane monomer having between 7and 120 dialkylsiloxane repeating units and which may be optionallysubstituted with at least one hydroxyl group;

optionally one or more monofunctional, hydroxyl-containing siloxanemonomer having less than 7 dialkylsiloxane repeating units, trialkylsiloxane groups or a combination thereof; with the proviso that if saidmonofunctional polydialkylsiloxane does not comprise at least onehydroxyl at least one monofunctional, hydroxyl-containing siloxanemonomer is included;

about 40-about 60 wt % of at least one slow reacting hydrophilicmonomer;

at least one hydroxyl containing hydrophilic monomer, wherein the molarratio of hydroxyl containing components to the slow reacting hydrophilicmonomer is between about 0.15 to about 0.4, wherein the reactive mixtureis free of diluent.

The present invention further relates to a silicone hydrogel comprising,consisting of, or consisting essentially of between about 8 and about 17wt % silicon, an advancing contact angle of less than about 80° withoutsurface modification formed from a reactive mixture comprising,consisting of, or consisting essentially of

at least one hydroxyl substituted, monofunctional polydialkylsiloxanemonomer having between 2 and 120 dialkylsiloxane repeating units;

optionally one or more monofunctional siloxane monomer having 7 to 120dialkylsiloxane repeating units, with the proviso that if saidmonofunctional, hydroxyl-containing siloxane monomer has less than 4dialkylsiloxane repeating units or is of Formula IX

Wherein R₃, R₁₂, X, R₁₅, R₁₇ and p are as defined herein, at least onemonofunctional, siloxane monomer having 7 to 120 dialkylsiloxanerepeating units is included;

about 40-about 60 wt % of at least one slow reacting hydrophilicmonomer;

at least one hydroxyl containing hydrophilic monomer, wherein the molarratio of hydroxyl containing components to the slow reacting hydrophilicmonomer is between about 0.15 to about 0.4, wherein the reactive mixtureis free of diluent.

The silicone hydrogels of the present invention are useful for makingbiomedical devices, ophthalmic devices, and particularly contact lenses.

DESCRIPTION OF THE FIGURE

FIG. 1 is a schematic of a lens assembly.

FIG. 2 is a schematic of the dual compartment cure box used for thekinetic evaluations.

FIG. 3 is a schematic of compartment 2 of the cure box show in FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to silicone hydrogels having a desirablebalance of properties which can be formed without diluents. The siliconehydrogels are formed from reactive mixtures comprising at least onehydroxyl substituted, monofunctional polydialkylsiloxane monomer havingbetween 2 and 120 dialkylsiloxane repeating units, at least one slowreacting hydrophilic monomer and at least one hydroxyl containinghydrophilic monomer. The resulting silicone hydrogels are surprisinglyeasy to process and display an exceptional balance of propertiesincluding haze, water content and oxygen permeability.

As used herein, “diluent” refers to a non-reactive solvent for thereactive components. Diluents do not react to form part of thebiomedical devices.

As used herein, a “biomedical device” is any article that is designed tobe used while either in or on mammalian tissues or fluid, or in or onhuman tissue or fluids. Examples of these devices include but are notlimited to catheters, implants, stents, and ophthalmic devices such asintraocular lenses, punctal plugs and contact lenses. In one embodiment,the biomedical devices are ophthalmic devices, particularly contactlenses, most particularly contact lenses made from silicone hydrogels.

As used herein, the terms “ophthalmic device” refers to products thatreside in or on the eye. As used herein, the terms “lens” and“ophthalmic device” refer to devices that reside in or on the eye. Thesedevices can provide optical correction, wound care, drug delivery,diagnostic functionality, cosmetic enhancement or effect, glarereduction, UV blocking or a combination of these properties.Non-limiting examples of ophthalmic devices include lenses, punctalplugs and the like. The term lens (or contact lens) includes but is notlimited to soft contact lenses, hard contact lenses, intraocular lenses,overlay lenses, ocular inserts, and optical inserts.

As used herein “reaction mixture” refers to reactive and non-reactivecomponents that are mixed together and reacted to form the siliconehydrogels of the present invention. The reactive components areeverything in the reaction mixture except the diluent and any additionalprocessing aids which do not become part of the structure of thepolymer.

As used herein “(meth)” refers to an optional methyl substitution. Thus,a term such as “(meth)acrylate” denotes both methacrylic and acrylicradicals.

All percentages in this specification are weight percentages unlessotherwise noted.

As used herein, the phrase “without a surface treatment” or “not surfacetreated” means that the exterior surfaces of the devices of the presentinvention are not separately treated to improve the wettability of thedevice. Treatments which may be foregone because of the presentinvention include, plasma treatments, grafting, coating and the like.Coatings which provide properties other than improved wettability, suchas, but not limited to antimicrobial coatings and the application ofcolor or other cosmetic enhancement, are not considered surfacetreatment.

As used herein “silicone macromers” and silicone “prepolymers” meanmono- and multi-functional silicone containing compounds havingmolecular weights of greater than about 2000.

As used herein “hydroxyl-containing component” is any componentcontaining at least one hydroxyl group.

As used herein “kinetic half life” means the time elapsed at the givenreaction conditions for 50% of the reactive component to be consumed.Kinetic half life may be calculated using the method and calculationsdescribed herein.

As used herein “monovalent reactive groups” are groups that can undergofree radical and/or cationic polymerization. Non-limiting examples offree radical reactive groups include (meth)acrylates, styryls, vinyls,vinyl ethers, C₁₋₆alkyl(meth)acrylates, (meth)acrylamides,C₁₋₆alkyl(meth)acrylamides, N-vinyllactams, N-vinylamides,C₂₋₁₂alkenyls, C₂₋₁₂alkenylphenyls, C₂₋₁₂alkenylnaphthyls,C₂₋₆alkenylphenylC₁₋₆alkyls, O-vinylcarbamates and O-vinylcarbonates.Non-limiting examples of cationic reactive groups include vinyl ethersor epoxide groups and mixtures thereof. Non-limiting examples of thefree radical reactive groups include (meth)acrylate, acryloxy,(meth)acrylamide, and mixtures thereof.

As used herein “hydrophilic” means water soluble. Hydrophilic componentsare those which are soluble in water at 25° C. and a concentration of 1weight part hydrophilic component to 9 weight parts water.

As used herein, “clear” means a haze value less than about 50%.

In the present invention the components are selected to react atspecific points in the reaction. For example, “fast reacting” componentsare selected to polymerize primarily at the beginning of the overallcopolymerization reaction, while the slow reacting hydrophilic monomeris selected to polymerize primarily at the end of the overallcopolymerization reaction. Fast reacting components include thesilicone-containing components, the hydroxyalkyl monomers and somecrosslinkers. In one embodiment slow reacting components have kinetichalf lives which are at least about two times greater than the fastestsilicone containing monomer. Kinetic half lives may be measured asdescribed herein. It should be appreciated that the kinetic half livesare relative to specific formulations.

Examples of slow reacting groups include (meth)acrylamides, vinyls,allyls and combinations thereof and a least one hydrophilic group. Inanother embodiment the slow reacting group is selected from N-vinylamides, O-vinyl carbamates, O-vinyl carbonates, N-vinyl carbamates,O-vinyl ethers, O-2-propenyl, wherein the vinyl or allyl groups may befurther substituted with a methyl group. In yet another embodiment theslow reacting group is selected from N-vinyl amides, O-vinyl carbonates,and O-vinyl carbamates.

Examples of fast reacting groups include (meth)acrylates, styryls,(meth)acryamides and mixtures thereof. Generally (meth)acrylates arefaster than (meth)acrylamides, and acrylamides are faster than(meth)acrylamides.

Throughout the specification, wherever chemical structures are given, itshould be appreciated that alternatives disclosed for the substituentson the structure may be combined in any combination. Thus if a structurecontained substituents R₁ and R₂, each of which contained three lists ofpotential groups, 9 combinations are disclosed. The same applies forcombinations of properties.

It has been surprisingly found that by selecting the components of thereaction mixture, silicone hydrogels having a desirable balance ofproperties may be formed without the use of a diluent.

Silicone hydrogels are formed by reacting a number of differentpolymerizable components to for a polymer. Silicone hydrogel reactivemixtures generally contain both hydrophilic components, which allow thepolymer to absorb substantially quantities of water, and siliconecomponents, which allow the polymer to transmit oxygen. Unfortunatelysilicone is highly hydrophobic, and the more silicone a component has,the less compatible it will be with hydrophilic components. Also, it isdesirable for some end uses, like contact lenses, for the resultingsilicone hydrogels to have a combination of both high water content (50%or more) and good oxygen permeability (greater than 60, or greater than80 barrers). However, because those properties come from differentcomponents, which can be incompatible, achieving this balance has beendifficult, and increasing one property (for example water content)generally results in decreasing another property (usually oxygenpermeability). Past attempts have required the use of diluents tocompatibilize the components. However, the diluents can be expensive,flammable and difficult to remove from the lenses, making manufacturingmore difficult.

It has been surprisingly found that a family of silicone hydrogelpolymers having a desirable balance of properties may be made withoutthe use of diluents. Many of these formulations have mechanicalproperties which allow them to be dry released from the lens molds,further simplifying the lens making process.

The silicone hydrogels of the present invention display a combination ofwater contents of at least about 50% and Dk values of at least about 60,or at least about 80. The silicone hydrogels are also clear.

The reaction mixtures of the present invention are diluent free,comprise about 40 and about 60 wt % of at least one slow-reactinghydrophilic monomer; at least one monofunctional, hydroxyl-containingsiloxane monomer; and at least one hydroxyl containing hydrophilicmonomer, wherein the molar ratio of hydroxyl containing components tothe slow reacting hydrophilic monomer is between about 0.15 to about0.4.

The first component of the reactive mixture is at least oneslow-reacting hydrophilic monomer. Slow-reacting hydrophilic monomerscomprises at least one slow reacting group and a least one hydrophilicgroup. The slow reacting group may be selected from N-vinyl amides,O-vinyl carbamates, O-vinyl carbonates, N-vinyl carbamates, O-vinylethers, O-2-propenyl, wherein the vinyl or allyl groups may be furthersubstituted with a methyl group. The slow reacting group may be selectedfrom N-vinyl amides, O-vinyl carbonates, and O-vinyl carbamates.Hydrophilic groups include hydroxyls, amines, ethers, amides, ammoniumgroups, carboxylic acid, carbamates, combinations thereof and the like.Suitable hydrophilic groups include hydroxyls, ethers, amides,carboxylic acid combinations thereof and the like. If a (meth)acrylamideis selected as the slow-reacting hydrophilic monomer, asilicone-containing monomer having a very short kinetic half life, suchas an acrylate must be used.

The slow-reacting hydrophilic monomer may be selected from N-vinylamidemonomer of Formula I, a vinyl pyrrolidone of Formula II-IV, and n-vinylpiperidone of Formula V:

wherein R is H or methyl, and in one embodiment R is H;

R₁, R₂, R₃, R₆, R₇, R₁₀, and R₁₁ are independently selected from H, CH₃,CH₂CH₃, CH₂CH₂CH₃, C(CH₃)₂;

R₄ and R₈ are independently selected from CH₂, CHCH₃ and —C(CH₃);

R₅ is selected from H, methyl, ethyl; and

R₉ is selected from CH═CH₂, CCH₃═CH₂, and CH═CHCH₃.

The total number of carbon atoms in R₁ and R₂ may be 4 or less,preferably R₁ and R₂ are methyl.

The slow-reacting hydrophilic monomer may be selected from the N-vinylamide monomer of Formula I or a vinyl pyrrolidone of Formula II or IV.In yet another embodiment R₆ is methyl, R₇ is hydrogen, R₉ is CH═CH₂,R₁₀ and R₁₁ are H.

In another embodiment the slow-reacting hydrophilic monomer is selectedfrom ethylene glycol vinyl ether (EGVE), di(ethylene glycol) vinyl ether(DEGVE), N-vinyl lactams, including N-vinyl pyrrolidone (NVP),1-methyl-3-methylene-2-pyrrolidone, 1-methyl-5-methylene-2-pyrrolidone,5-methyl-3-methylene-2-pyrrolidone; 1-ethyl-5-methylene-2-pyrrolidone,N-methyl-3-methylene-2-pyrrolidone, 5-ethyl-3-methylene-2-pyrrolidone,1-n-propyl-3-methylene-2-pyrrolidone,1-n-propyl-5-methylene-2-pyrrolidone,1-isopropyl-3-methylene-2-pyrrolidone,1-isopropyl-5-methylene-2-pyrrolidone, N-vinyl-N-methyl acetamide (VMA),N-vinyl-N-ethyl acetamide, N-vinyl-N-ethyl formamide, N-vinyl formamide,N-vinyl acetamide, N-vinyl isopropylamide, allyl alcohol, N-vinylcaprolactam, N-2-hydroxyethyl vinyl carbamate, N-carboxyvinyl-β-alanine(VINAL), N-carboxyvinyl-α-alanine and mixtures thereof.

In another embodiment the slow-reacting hydrophilic monomer is selectedfrom N-vinylpyrrolidone, N-vinylacetamide,1-methyl-3-methylene-2-pyrrolidone, 1-methyl-5-methylene-2-pyrrolidone,5-methyl-3-methylene-2-pyrrolidone, and mixtures thereof. In yet anotherembodiment the slow-reacting hydrophilic monomer is selected from NVP,VMA and 1-methyl-5-methylene-2-pyrrolidone. In yet another embodimentthe slow-reacting hydrophilic monomer comprises NVP.

The diluent-free formulations of the present invention further compriseat least one fast-reacting, monofunctional, hydroxyl-containing siloxanecomponent which comprises at least 2 alkyl siloxane groups. In someembodiments the at least one monofunctional, hydroxyl-containingsiloxane component comprises a polydialkyl siloxane having between about4 and about 120, between about 4 and about 60 and between about 4 and inother embodiments about 30 repeating units. The alkyl siloxane groupscan be dialkyl siloxane groups, trialkyl siloxane groups or acombination thereof, however, highly branched siloxane groups, such astris(trimethyl siloxane) groups are not preferred as they provideundesirable mechanical properties to the resulting polymers. Thus, inone embodiment, the silicone hydrogels are formed from reactive mixtureswhich comprise less than about 10%, less than 5% and 0% TRIS.

When a single siloxane-containing component is desired, the at least onefast reacting, monofunctional, hydroxyl-containing siloxane componentwill comprise a sufficient number of alkyl siloxane groups to providethe resulting silicone hydrogel with between about 8 and about 17 wt %silicon, based upon the weight of the copolymer, not including water.Suitable at least one fast-reacting, monofunctional, hydroxyl-containingsiloxane component for this embodiment will comprise between about 4 andabout 120, between about 6 and about 60 and in other embodiments betweenabout 6 and about 30 dialkyl siloxane repeating units.

In another embodiment the reaction mixtures of the present inventioncomprise at least one monofunctional, hydroxyl-containing siloxanecomponent which comprises at least 2 alkyl siloxane groups and at leastone monofunctional, siloxane monomer having 7 to 120 dialkylsiloxanerepeating units, between about 4 and about 60 and between about 4 and inother embodiments about 30 repeating units.

The at least one monofunctional, siloxane monomer comprises (a) a fastreacting group and (b) a polydialkyl siloxane chain. In anotherembodiment the at least one monofunctional, siloxane monomer comprises areactive group selected from (meth)acrylates, styryls, (meth)acrylamidesand mixtures thereof. The monofunctional, siloxane monomer may alsocontain at least one fluorine. In yet another embodiment themonofunctional, siloxane monomer is selected frommono(meth)acryloxyalkyl polydialkylsiloxane monomer of Formula VII orthe styryl polydialkylsiloxane monomer of Formula VIII:

wherein R₁₂ is H or methyl;

X is O or NR₁₆,

Each R₁₄ is independently a C₁ to C₄ alkyl which may be fluorinesubstituted, or phenyl, and in another embodiment each R₁₄ isindependently selected from ethyl and methyl groups, and in yet anotherembodiment, all R₁₄ are methyl or at least one R₁₄ may be3,3,3-trifluoropropyl.

R₁₂ and each R₁₄ may be methyl.

R₁₅ is a C₁ to C₄ alkyl;

R₁₃ is a divalent alkyl group, which may further be functionalized witha group selected from the group consisting of ether groups, hydroxylgroups, carbamate groups and combinations thereof, and in anotherembodiment C₁-C₆ alkylene groups which may be substituted with ether,hydroxyl and combinations thereof, and in yet another embodiment C₁ orC₃-C₆ alkylene groups which may be substituted with ether, hydroxyl andcombinations thereof; a is 7 to 120, 7-60 and in some embodiments 7 to30.

R₁₆ is selected from H, C₁₋₄ alkyl, which may be further substitutedwith one or more hydroxyl groups, and in some embodiments is H ormethyl.

In yet another embodiment R₁₂ and each R₁₄ are methyl.

In yet another embodiment at least one R₁₄ is 3,3,3-trifluoropropyl.

In one embodiment the at least one monofunctional, siloxane monomer isselected from mono(meth)acryloxyalkyl polydialkylsiloxane monomer ofFormula VII. Examples of suitable silicone-containing monomers includemonomethacryloxyalkylpolydimethylsiloxane methacrylates selected fromthe group consisting of monomethacryloxypropyl terminated mono-n-butylterminated polydimethylsiloxane, monomethacryloxypropyl terminatedmono-n-methyl terminated polydimethylsiloxane, monomethacryloxypropylterminated mono-n-butyl terminated polydiethylsiloxane,monomethacryloxypropyl terminated mono-n-methyl terminatedpolydimethylsiloxane, N-(2,3-dihydroxypropane)-N′-(propyltetra(dimethylsiloxy)dimethylbutylsilane)acrylamide,α-(2-hydroxy-1-methacryloxypropyloxypropyl)-ω-butyl-decamethylpentasiloxane,and mixtures thereof.

In another embodiment the silicone-containing component is selected fromthe group consisting of monomethacryloxypropyl terminated mono-n-butylterminated polydimethylsiloxane, monomethacryloxypropyl terminatedmono-n-methyl terminated polydimethylsiloxane,N-(2,3-dihydroxypropane)-N′-(propyltetra(dimethylsiloxy)dimethylbutylsilane)acrylamide,α-(2-hydroxy-1-methacryloxypropyloxypropyl)-ω-butyl-decamethylpentasiloxane,and mixtures thereof.

In another embodiment the silicone containing component is selected fromacrylamide silicones of US20110237766, and particularly the siliconemonomers expressed in the following general formulae (s1) through (s6).

wherein m is 4-12 and in some embodiments 4-10.

Additional silicone containing components may also be included. Anyadditional disclosed silicone components having the herein disclosedreactive groups may be included. Examples include silicone containingmonomers displaying branched siloxane chains such as SiMAA and TRIS.

The at least one mono-functional silicone-containing monomer is presentin the reactive mixture in an amount sufficient to provide the desiredoxygen permeability. It is a benefit of the present invention thatoxygen permeabilities greater than about 80 barrer, in some embodimentsgreater than about 90 barrer, and in other embodiments greater thanabout 100 barrer may be achieved. Suitable amounts will depend on thelength of the siloxane chain included in the silicone-containingmonomers, with silicone-containing monomers having longer chainsrequiring less monomer. Amounts include from about 20 to about 60 weight%, and in some embodiments from about 30 to about 55 weight %.

When the mono-functional silicone-containing monomer does not contain atleast one hydroxyl group, the reaction mixtures of the present inventionfurther comprise at least one monofunctional, hydroxyl-containingsiloxane component which comprises at least 2 alkyl siloxane groups. Themonofunctional, hydroxyl-containing siloxane component contains the samereactive functionality as the mono-functional silicone-containingmonomer. In some embodiments the monofunctional, hydroxyl-containingsiloxane component is a compound of Formula IX

where R₁₂, R₃, R₁₅, X are as defined above,

p is 4-20, and in some embodiments 4-12

R₁₈ is a divalent alkyl group substituted with at least one hydroxylgroup, which may further be functionalized with a group selected fromthe group consisting of ether groups, carbamate groups and combinationsthereof, and in another embodiment C₁-C₆ alkylene groups substitutedwith at least one hydroxyl group which may also be substituted with atleast one ether group, and in yet another embodiment C₁ or C₃-C₆alkylene groups substituted with at least one hydroxyl group which mayalso be substituted with at least one ether group;

R₁₇ is selected from R₁₄ or trimethylsiloxy groups.

Examples of monofunctional, hydroxyl-containing siloxane componentsinclude3-(methacryloxy-2-hydroxypropoxy)propylbis(trimethylsiloxy)methylsilane, (SimMA),α-(2-hydroxy-1-methacryloxypropyloxypropyl)-w-butyl-octamethylpentasiloxane,N-(2,3-dihydroxypropane)-N′-(propyltetra(dimethylsiloxy)dimethylbutylsilane)acrylamide:

and monomers of the following structures:

In another embodiment the monofunctional, hydroxyl-containing siloxanecomponent comprisesα-(2-hydroxy-1-methacryloxypropyloxypropyl)-ω-butyl-octamethylpentasiloxane.

In one embodiment the reaction mixture is substantially free of TRIS,and in another is substantially free of silicone containing macromers orprepolymers having a number average molecular weight greater than about8,000 and in another embodiment greater than about 5,000.

The reaction mixtures of the present invention further comprise at leastone hydroxyalkyl monomer selected from hydroxyalkyl(meth)acrylate or(meth)acrylamide monomer of Formula X or a styryl compound of Formula XI

wherein R₁ is H or methyl,

X is O or NR₄, R₄ is a H, C₁ to C₄ alkyl, which may be furthersubstituted with at least one OH, in some embodiments methyl or2-hydroxyethyl; and

R is selected from C₂-C₄ mono or dihydroxy substituted alkyl, andpoly(ethylene glycol) having 1-10 repeating units; and in someembodiments 2-hydroxyethyl, 2,3-dihydroxypropyl, or 2-hydroxypropyl.

In one embodiment R₁ is H or methyl, X is oxygen and R is selected fromC₂-C₄ mono or dihydroxy substituted alkyl, and poly(ethylene glycol)having 1-10 repeating units. In another embodiment R₁ methyl, X isoxygen and R is selected from C₂-C₄ mono or dihydroxy substituted alkyl,and poly(ethylene glycol) having 2-20 repeating units, and in yetanother embodiment R₁ methyl, X is oxygen and R is selected from C₂-C₄mono or dihydroxy substituted alkyl. In one embodiment, at least onehydroxyl group is on the terminal end of the R alkyl group.

Examples of suitable hydroxyalkyl monomers include 2-hydroxyethylmethacrylate, 2-hydroxyethyl acrylate, 3-hydroxypropyl(meth)acrylate,2-hydroxypropyl(meth)acrylate, 1-hydroxypropyl-2-(meth)acrylate,2-hydroxy-2-methyl-propyl(meth)acrylate,3-hydroxy-2,2-dimethyl-propyl(meth)acrylate,4-hydroxybutyl(meth)acrylate, glycerol(meth)acrylate,2-hydroxyethyl(meth)acrylamide, polyethyleneglycol monomethacrylate,bis-(2-hydroxyethyl)(meth)acrylamide,2,3-dihydroxypropyl(meth)acrylamide, and mixtures thereof.

In another embodiment the hydroxyalkyl monomer is selected from thegroup consisting of 2-hydroxyethyl methacrylate, glycerol methacrylate,2-hydroxypropyl methacrylate, hydroxybutyl methacrylate,3-hydroxy-2,2-dimethyl-propyl methacrylate, and mixtures thereof.

In yet another embodiment the hydroxyalkyl monomer comprises2-hydroxyethyl methacrylate, and in another embodiment comprises3-hydroxy-2,2-dimethyl-propyl methacrylate. In an alternate embodimentthe reactive hydroxyalkyl monomer comprises glycerol methacrylate.

In one embodiment, the hydroxyl containing components have the samereactive functionality as the silicone-containing monomers.

The hydroxyalkyl monomers are present in mole percents which form amolar ratio of hydroxyl groups to slow reacting hydrophilic monomer ofat least about 0.15 and in some embodiments between about 0.15 and about0.4. This is calculated by dividing the number of moles of hydroxylgroups in the hydroxyalkyl monomers (including any hydroxyl groups onthe slow-reacting hydrophilic monomer and the silicone-containingmonomer) by the number of moles of the slow-reacting hydrophilic monomerper a given mass of the monomer mix. In this embodiment, for a reactionmixture comprising HO-mPDMS, HEMA, EGVE and NVP, the hydroxyl groups oneach of HO-mPDMS, HEMA and EGVE would be counted. Any hydroxyl groupspresent in the diluent (if used) are not included in the calculation. Inone embodiment, the lower amount of hydroxyalkyl monomers is selected toprovide a haze value to the final lens of less than about 50% and insome embodiments less than about 30%.

Alternatively, the molar ratio of all hydroxyl groups on reactioncomponents in the reaction mixture to silicon (HO:Si) is between about0.16 and about 0.4. The molar ratio is calculated by dividing molarconcentration of hydroxyl groups in the components of the reactivemixture (other than any hydroxyls which are part of the slow-reactinghydrophilic monomer or diluents) by the molar concentration of silicon.In this embodiment both the hydroxyalkyl monomers and anyhydroxyl-containing silicone components are included in the calculation.Thus, in calculating the HO:Si ratio of the reaction mixture comprisingHO-mPDMS, HEMA, NVP and EGVE, only the hydroxyl groups on each ofHO-mPDMS, HEMA would be counted in calculating the HO:Si.

It will be appreciated that the minimum amount of hydroxyl componentwill vary depending upon a number of factors, including, the number ofhydroxyl groups on the hydroxyalkyl monomer, the amount, molecularweight and presence or absence of hydrophilic functionality on thesilicone containing components. For example, where HEMA is used as thehydroxyalkyl monomer and mPDMS is used in amounts about 38 wt % as thesole silicone containing monomer, at least about 8 wt % HEMA (0.16HO:Si) is included to provide the desired haze values. However, whenlesser amounts of mPDMS are used (about 20%), as little as about 2 or 3%HEMA provides silicone hydrogel contact lenses having haze values belowabout 50%. Similarly, when the formulation includes substantial amountsof a hydroxyl-containing silicone component (such as greater than about20 wt % HO-mPDMS as in Examples 68-73), amounts of HEMA as low as about7 wt % (0.13 HO:Si, or 0.24 HO_(total):Si) may provide the desired levelof haze.

Where Dk values greater than about 60, 80 or 100 barrers are desired, anexcess of hydroxyalkyl monomer beyond what is necessary to achieve thedesired haze is not desirable.

The reactive mixture may further comprise additional hydrophilicmonomers. Any hydrophilic monomers used to prepare hydrogels may beused. For example monomers containing acrylic groups (CH₂═CROX, where Ris hydrogen or C₁₋₆alkyl an X is O or N) or vinyl groups (—C═CH₂) may beused. Examples of additional hydrophilic monomers areN,N-dimethylacrylamide, polyethyleneglycol monomethacrylate, methacrylicacid, acrylic acid, combinations thereof and the like.

The reaction mixtures of the present invention may additionally compriseat least one crosslinker.

Suitable crosslinkers include monomers with two or more polymerizabledouble bonds, such as ethylene glycol dimethacrylate (“EGDMA”),trimethylolpropane trimethacrylate (“TMPTMA”), glycerol trimethacrylate,polyethylene glycol dimethacrylate (wherein the polyethylene glycolpreferably has a molecular weight up to, e.g., about 5000), and otherpolyacrylate and polymethacrylate esters, such as the end-cappedpolyoxyethylene polyols described above containing two or more terminalmethacrylate moieties. The amount of crosslinker is balanced with theamount and types of silicone components selected to achieve the desiredmodulus. Suitable amounts include molar concentrations between about 0.6to about 2.4 mmole/100 g of reactive components in the reaction mixtureand in some embodiments between about 0.6 to about 1.8 mmole/100 greactive components. Alternatively, if the hydrophilic monomers and/orthe silicone containing monomers act as the cross-linking agent, theaddition of a crosslinking agent to the reaction mixture is optional.Examples of hydrophilic monomers which can act as the crosslinking agentand when present do not require the addition of an additionalcrosslinking agent to the reaction mixture include polyoxyethylenepolyols described above containing two or more terminal methacrylatemoieties.

An example of a silicone containing monomer which can act as acrosslinking agent and, when present, does not require the addition ofan additional crosslinking monomer to the reaction mixture includesα,ω-bismethacryloypropyl polydimethylsiloxane.

The reaction mixtures can also contain multiple crosslinkers dependingon the reaction rate of the hydrophilic component. With very slowreacting hydrophilic components (e.g. VMA, EGVE, DEGVE) crosslinkershaving slow reacting functional groups (e.g. di-vinyl, tri-vinyl,di-allyl, tri-allyl) or a combination of slow reacting functional groupsand fast reacting functional groups (e.g. HEMAVc) can be combined withcrosslinkers having fast reacting functional groups ((meth)acrylates) toimprove the retention of the polymers of the slow-reacting monomers inthe final hydrogel.

In one embodiment the reaction mixture comprises at least twocrosslinkers, at least one first crosslinker having functional groupswhich will react with the silicone components and hydroxylalkyl(meth)acrylates and at least one second crosslinker havingfunctional groups which react with the slow reacting hydrophilicmonomer. This mixture of fast and slow reacting crosslinkers providesthe final polymer with improved resilience and recovery, particularly onthe surface of the lens. Examples of suitable first crosslinkers includethose having only (meth)acrylate functionality, such as EGDMA, TEGDMAand combinations thereof. Examples of suitable second crosslinkersinclude those having only vinyl functionality, such as triallylcyanurate (TAC). When mixtures are used, suitable amounts of allcrosslinker in the reactive mixture include between about 0.10% andabout 1%, and about 0.1 to about 0.5% wt, excluding diluentrespectively. In another embodiment the total amount of all crosslinkerin the reactive mixtures is between 0.7 to about 6.0 mmol/100 g ofpolymerizable components; between about 0.7 to about 4.0 mmoles per 100g of reactive components. The fast and slow reacting crosslinkers arepresent in respective amounts of about 0.30 to about 2.0 mmol/100 g ofpolymerizable components; and between about 0.4 to about 2.0 mmoles per100 g of reactive components.

The reaction mixture may also comprise at least one UV absorbingcompound. Suitable UV absorbers may be derived from2-(2′-hydroxyphenyl)benzotriazoles, 2-hydroxybenzophenones,2-hydroxyphenyltriazines, oxanilides, cyanoacrylates, salicylates and4-hydroxybenzoates; which may be further reacted to incorporate reactivepolymerizable groups, such as (meth)acrylates. Specific examples of UVabsorbers which include polymerizable groups include2-(2′-hydroxy-5-methacrylyloxyethylphenyl)-2H-benzotriazole (Norbloc),5-vinyl and 5-isopropenyl derivatives of2-(2,4-dihydroxyphenyl)-2H-benzotriazole and 4-acrylates or4-methacrylates of 2-(2,4-dihydroxyphenyl)-2H-benzotriazole or2-(2,4-dihydroxyphenyl)-1,3-2H-dibenzotriazole, mixtures thereof and thelike. When a UV absorber is included, it may be included in amountsbetween about 0.5 and about 4 wt. %, and in other embodiments betweenabout 1 wt % and about 2 wt %.

A polymerization initiator is preferably included in the reactionmixture. The polymerization initiators includes compounds such aslauroyl peroxide, benzoyl peroxide, isopropyl percarbonate,azobisisobutyronitrile, and the like, that generate free radicals atmoderately elevated temperatures, photoinitiator systems such as anaromatic alpha-hydroxy ketone and a tertiary amine plus a diketone.Illustrative examples of photoinitiator systems are 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one,bis(2,6-dimethoxybenzoyl)-2,4-4-trimethylpentyl phosphine oxide(DMBAPO), and a combination of camphorquinone and ethyl4-(N,N-dimethylamino)benzoate.

In one embodiment, the reaction mixtures of the present inventioncomprise at least one photoinitiator. The use of photoinitiationprovides desirable cure times (time to reach essentially complete cure)of less than about 30 minutes, less than about 20 minutes and in someembodiments less than about 15 minutes. Suitable photoinitiator systemsinclude aromatic alpha-hydroxy ketones, alkoxyoxybenzoins,acetophenones, acylphosphine oxides, bisacylphosphine oxides, and atertiary amine plus a diketone, mixtures thereof and the like.Illustrative examples of photoinitiators are 1-hydroxycyclohexyl phenylketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one,bis(2,6-dimethoxybenzoyl)-2,4-4-trimethylpentyl phosphine oxide(DMBAPO), bis(2,4,6-trimethylbenzoyl)-phenyl phosphineoxide (Irgacure819), 2,4,6-trimethylbenzyldiphenyl phosphine oxide and2,4,6-trimethylbenzoyl diphenylphosphine oxide, benzoin methyl ester anda combination of camphorquinone and ethyl 4-(N,N-dimethylamino)benzoate.Commercially available visible light initiator systems include Irgacure819, Irgacure 1700, Irgacure 1800, Irgacure 819, Irgacure 1850 (all fromCiba Specialty Chemicals) and Lucirin TPO initiator (available fromBASF). Commercially available UV photoinitiators include Darocur 1173and Darocur 2959 (Ciba Specialty Chemicals). These and otherphotoinitiators which may be used are disclosed in Volume III,Photoinitiators for Free Radical Cationic & Anionic Photopolymerization,2^(nd) Edition by J. V. Crivello & K. Dietliker; edited by G. Bradley;John Wiley and Sons; New York; 1998, which is incorporated herein byreference. The initiator is used in the reaction mixture in effectiveamounts to initiate photopolymerization of the reaction mixture, e.g.,from about 0.1 to about 2 parts by weight per 100 parts of reactivemonomer.

In some embodiments inhibitors may also be included. Free radicalinhibitors are compounds that react rapidly with propagating radicals toproduce stable radical species that terminate the chain. Classes ofinhibitors include quinones, substituted phenols, secondary aromaticamines, lactones and nitro compounds. Specific examples of inhibitorsinclude BHT, MEHQ, hydroxyamines, benzofuranone derivatives, molecularoxygen, vitamin E, nitric oxide/nitrogen dioxide mixtures (which formnitroxides in situ) mixtures and combinations thereof and the like.

Some inhibitors may be included with the monomers which are selected.Inhibitors may also be intentionally added to the reaction mixtures ofthe present application. The amount of inhibitor which may be includedis from about 100 to about 2,500 μgm/gm of reaction mixture.

Polymerization of the reaction mixture can be initiated using theappropriate choice visible or ultraviolet light. Alternatively,initiation can be conducted without a photoinitiator using, for example,e-beam. In another embodiment the initiators are selected frombisacylphosphine oxides, such as bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (Irgacure 819®) or a combination of 1-hydroxycyclohexylphenyl ketone and bis(2,6-dimethoxybenzoyl)-2,4-4-trimethylpentylphosphine oxide (DMBAPO). In one embodiment a preferred method ofpolymerization initiation is visible light. In anotherbis(2,4,6-trimethylbenzoyl)-phenyl phosphine oxide (Irgacure 819®) isthe photo initiator.

The reaction mixtures of the present invention are formed withoutdiluent, or “neat”.

The reactive mixture may contain additional components such as, but notlimited to, medicinal agents, antimicrobial compounds, reactive tints,pigments, copolymerizable and non-polymerizable dyes, release agents andcombinations thereof.

Combinations of reactive components include those having from about 30to about 50 weight % silicone containing monomers (including bothmonofunctional silicone-containing monomers and monofunctionalhydroxyl-containing siloxane components), about 40 to about 60 weight %at least one slow-reacting monomer, from about 1 to about 15 weight % ofan hydroxyalkyl monomer (all based upon the weight % of all reactivecomponents).

The reaction mixtures of the present invention can be formed by any ofthe methods known to those skilled in the art, such as shaking orstirring, and used to form polymeric articles or devices by knownmethods.

For example, the biomedical devices of the invention may be prepared bymixing reactive components with a polymerization initiator and curing byappropriate conditions to form a product that can be subsequently formedinto the appropriate shape by lathing, cutting and the like.Alternatively, the reaction mixture may be placed in a mold andsubsequently cured into the appropriate article.

Various processes are known for processing the reaction mixture in theproduction of contact lenses, including spincasting and static casting.Spincasting methods are disclosed in U.S. Pat. Nos. 3,408,429 and3,660,545, and static casting methods are disclosed in U.S. Pat. Nos.4,113,224 and 4,197,266. In one embodiment, the method for producingcontact lenses comprising the polymer of this invention is by the directmolding of the silicone hydrogels, which is economical, and enablesprecise control over the final shape of the hydrated lens. For thismethod, the reaction mixture is placed in a mold having the shape of thefinal desired silicone hydrogel, i.e., water-swollen polymer, and thereaction mixture is subjected to conditions whereby the monomerspolymerize, to thereby produce a polymer in the shape of the finaldesired product.

Referring to FIG. 1, a diagram is illustrated of an ophthalmic lens 100,such as a contact lens, and mold parts 101-102 used to form theophthalmic lens 100. In some embodiments, the mold parts include a backsurface mold part 101 and a front surface mold part 102. As used herein,the term “front surface mold part” refers to the mold part whose concavesurface 104 is a lens forming surface used to form the front surface ofthe ophthalmic lens. Similarly, the term “back surface mold part” refersto the mold part 101 whose convex surface 105 forms a lens formingsurface, which will form the back surface of the ophthalmic lens 100. Insome embodiments, mold parts 101 and 102 are of a concavo-convex shape,preferably including planar annular flanges, which surround thecircumference of the uppermost edges of the concavo-convex regions ofthe mold parts 101-102.

Typically, the mold parts 101-102 are arrayed as a “sandwich”. The frontsurface mold part 102 is on the bottom, with the concave surface 104 ofthe mold part facing upwards. The back surface mold part 101 can bedisposed symmetrically on top of the front surface mold part 102, withthe convex surface 105 of the back surface mold part 101 projectingpartially into the concave region of the front surface mold part 102. Inone embodiment, the back surface mold part 101 is dimensioned such thatthe convex surface 105 thereof engages the outer edge of the concavesurface 104 of the front mold part 102 throughout its circumference,thereby cooperating to form a sealed mold cavity in which the ophthalmiclens 100 is formed.

In some embodiments, the mold parts 101-102 are fashioned ofthermoplastic and are transparent to polymerization-initiating actinicradiation, by which is meant that at least some, and in some embodimentsall, radiation of an intensity and wavelength effective to initiatepolymerization of the reaction mixture in the mold cavity can passthrough the mold parts 101-102.

For example, thermoplastics suitable for making the mold parts caninclude: polystyrene; polyvinylchloride; polyolefin, such aspolyethylene and polypropylene; copolymers or mixtures of styrene withacrylonitrile or butadiene, polyacrylonitrile, polyamides, polyesters,cyclic olefin copolymers such as Topas available from Ticona or Zeonoravailable from Zeon, combinations, such as blends or copolymers of anyof the foregoing, or other known materials.

Following polymerization of the reaction mixture to form a lens 100, thelens surface 103 will typically adhere to the mold part surface 104. Thesteps of the present invention facilitate release of the surface 103from the mold part surface. The first mold part 101 can be separatedfrom the second mold part 102 in a demolding process. In someembodiments, the lens 100 will have adhered to the second mold part 102(i.e. the front curve mold part) during the cure process and remain withthe second mold part 102 after separation until the lens 100 has beenreleased from the front curve mold part 102. In other embodiments, thelens 100 can adhere to the first mold part 101.

The lens 100 may be removed from the mold part may be released from themold by any process, including contacting with a solvent or dry release.In one embodiment, the lenses may be released from the mold dry, byapplication of mechanical force.

In another embodiment, the lens 100 and the mold part to which it isadhered after demolding are contacted with an aqueous solution. Theaqueous solution can be heated to any temperature below the boilingpoint of the aqueous solution. Heating can be accomplished with a heatexchange unit to minimize the possibility of explosion, or by any otherfeasible means or apparatus for heating a liquid.

As used herein, processing includes the steps of removing the lens fromthe mold and contacting the lens with an aqueous solution. The steps maybe done separately, or in a single step or stage. The processingtemperature may be any temperatures between about 30° C. and the boilingpoint of the aqueous solutions, in some embodiments between about 30° C.and about 95° C., and in some embodiments between about 50° C. and about95° C.

The aqueous solution is primarily water. In some embodiments, theaqueous solution is at least about 70 wt % water, and in otherembodiments at least about 90 weight % water and in other embodiments atleast about 95%. The aqueous solution may also be a contact lenspackaging solution such as borate buffered saline solution, sodiumborate solutions, sodium bicarbonate solutions and the like. The aqueoussolution may also include additives, such as surfactants, preservatives,release aids, antibacterial agents, pharmaceutical and nutriceuticalcomponents, lubricants, wetting agents, salts, buffers, mixtures thereofand the like. Specific examples of additives which may be included inthe aqueous solution include Tween 80, which is polyoxyethylene sorbitanmonooleate, Tyloxapol, octylphenoxy(oxyethylene)ethanol, amphoteric 10),EDTA, sorbic acid, DYMED, chlorhexadine gluconate, hydrogen peroxide,thimerosal, polyquad, polyhexamethylene biguanide, mixtures thereof andthe like. Where various zones are used, different additives may beincluded in different zones. In some embodiments, additives can be addedto the hydration solution in amounts varying between 0.01% and 10% byweight, but cumulatively less than about 10% by weight.

Exposure of the ophthalmic lens 100 to the aqueous solution can beaccomplished by any method, such as washing, spraying, soaking,submerging, or any combination of the aforementioned. For example, insome embodiments, the lens 100 can be washed with an aqueous solutioncomprising deionized water in a hydration tower.

In embodiments using a hydration tower, front curve mold parts 102containing lenses 100 can be placed in pallets or trays and stackedvertically. The aqueous solution can be introduced at the top of thestack of lenses 100 so that the solution will flow downwardly over thelenses 100. The solution can also be introduced at various positionsalong the tower. In some embodiments, the trays can be moved upwardlyallowing the lenses 100 to be exposed to increasingly fresher solution.

In other embodiments, the ophthalmic lenses 100 are soaked or submergedin the aqueous solution.

The contacting step can last up to about 12 hours, in some embodimentsup to about 2 hours and in other embodiments from about 2 minutes toabout 2 hours; however, the length of the contacting step depends uponthe lens materials, including any additives, the materials that are usedfor the solutions or solvents, and the temperatures of the solutions.Sufficient treatment times typically shrink the contact lens and releasethe lens from the mold part. Longer contacting times will providegreater leaching.

The volume of aqueous solution used may be any amount greater than about1 ml/lens and in some embodiments greater than about 5 ml/lens.

In some methods, after separation or demolding, the lenses on the frontcurves, which may be part of a frame, are mated with individual concaveslotted cups to receive the contact lenses when they release from thefront curves. The cups can be part of a tray. Examples can include trayswith 32 lenses each, and 20 trays that can be accumulated into amagazine.

According to another embodiment of the present invention the lenses aresubmerged in the aqueous solution. In one embodiment, magazines can beaccumulated and then lowered into tanks containing the aqueous solution.The aqueous solution may also include other additives as describedabove. The ophthalmic devices, and particularly ophthalmic lenses of thepresent invention have a balance of properties which makes themparticularly useful. Such properties include clarity, optics, watercontent, oxygen permeability and contact angle. Thus, in one embodiment,the biomedical devices are contact lenses having a water content ofgreater than about 55%, greater than about 60%.

As used herein clarity means substantially free from visible haze. Clearlenses have a haze value of less than about 70%, more preferably lessthan about 50% and in some embodiments less than about 10% using one ofthe haze tests described herein.

Suitable oxygen permeabilities include those greater than about 80barrer and in some embodiments greater than about 85 barrer, and inother embodiments at least about 100 barrer.

Also, the biomedical devices, and particularly ophthalmic devices andcontact lenses have moduli which are less than about 150 psi, and insome embodiments less than about 100 psi.

The biomedical devices, and particularly ophthalmic devices and contactlenses have average contact angles (advancing) which are less than about80°, less than about 75° and in some embodiments less than about 70°. Insome embodiments the articles of the present invention have combinationsof the above described oxygen permeability, water content and contactangle. All combinations of the above ranges are deemed to be within thepresent invention.

Haze Measurement

Haze is measured by placing a hydrated test lens in borate bufferedsaline in a clear 20×40×10 mm glass cell at ambient temperature above aflat black background, illuminating from below with a fiber optic lamp(Dolan-Jenner PL-900 fiber optic light or Titan Tool Supply Co. fiberoptic light with 0.5″ diameter light guide set at a power setting of4-5.4) at an angle 66° normal to the lens cell, and capturing an imageof the lens from above, normal to the lens cell with a video camera (DVC1300C:19130 RGB camera with Navitar TV Zoom 7000 zoom lens) placed 14 mmabove the lens platform. The background scatter is subtracted from thescatter of the lens by subtracting an image of a blank cell using EPIXXCAP V 2.2 software. The subtracted scattered light image isquantitatively analyzed, by integrating over the central 10 mm of thelens, and then comparing to a −1.00 diopter CSI Thin Lens®, which isarbitrarily set at a haze value of 100, with no lens set as a haze valueof 0. Five lenses are analyzed and the results are averaged to generatea haze value as a percentage of the standard CSI lens. Lenses have hazelevels of less than about 150% (of CSI as set forth above) and in someembodiments less than about 100%.

Alternatively, instead of a −1.00 diopter CSI Thin Lenses®, a series ofaqueous dispersions of stock latex spheres (commercially available as0.49 μm Polystyene Latex Spheres—Certified Nanosphere Size Standardsfrom Ted Pella, Inc., Product Number 610-30) can be used as standards. Aseries of calibration samples were prepared in deionized water. Eachsolution of varying concentration was placed in a cuvette (2 mm pathlength) and the solution haze was measured using the above method.

Concentration Mean Solution (wt % × 10⁻⁴) GS 1 10.0 533 2 6.9 439 3 5.0379 4 4.0 229 5 2.0 172 6 0.7 138 Mean GS = mean gray scaleA corrective factor was derived by dividing the slope of the plot ofMean GS against the concentration (47.1) by the slope of anexperimentally obtained standard curve, and multiplying this ratio timesmeasured scatter values for lenses to obtain GS values.

“CSI haze value” may be calculated as follows:CSI haze value=100×(GS−BS)/(217−BS)Where GS is gray scale and BS is background scatter.Water ContentThe water content of contact lenses was measured as follows: Three setsof three lenses are allowed to sit in packing solution for 24 hours.Each lens is blotted with damp wipes and weighed. The lenses are driedat 60° C. for four hours at a pressure of 0.4 inches Hg or less. Thedried lenses are weighed. The water content is calculated as follows:

${\%\mspace{14mu}{water}\mspace{14mu}{content}} = {\frac{\left( {{{wet}\mspace{14mu}{weight}} - {{dry}\mspace{14mu}{weight}}} \right)}{{wet}\mspace{14mu}{weight}} \times 100}$The average and standard deviation of the water content are calculatedfor the samples and are reported.Modulus

Modulus is measured by using the crosshead of a constant rate ofmovement type tensile testing machine equipped with a load cell that islowered to the initial gauge height. A suitable testing machine includesan Instron model 1122. A dog-bone shaped sample having a 0.522 inchlength, 0.276 inch “ear” width and 0.213 inch “neck” width is loadedinto the grips and elongated at a constant rate of strain of 2 in/min.until it breaks. The initial gauge length of the sample (Lo) and samplelength at break (Lf) are measured. Twelve specimens of each compositionare measured and the average is reported. Percent elongation is=[(Lf−Lo)/Lo]×100. Tensile modulus is measured at the initial linearportion of the stress/strain curve.

Advancing Contact Angle

All contact angles reported herein are advancing contact angles. Theadvancing contact angle was measured as follows. Four samples from eachset were prepared by cutting out a center strip from the lensapproximately 5 mm in width and equilibrated in packing solution. Thewetting force between the lens surface and borate buffered saline ismeasured at 23° C. using a Wilhelmy microbalance while the sample isbeing immersed into or pulled out of the saline. The following equationis usedF=2γp cos θ or θ=cos⁻¹(F/2γp)where F is the wetting force, γ is the surface tension of the probeliquid, p is the perimeter of the sample at the meniscus and θ is thecontact angle. The advancing contact angle is obtained from the portionof the wetting experiment where the sample is being immersed into thepacking solution. Each sample was cycled four times and the results wereaveraged to obtain the advancing contact angles for the lens.Oxygen Permeability (Dk)

The Dk is measured as follows. Lenses are positioned on a polarographicoxygen sensor consisting of a 4 mm diameter gold cathode and a silverring anode then covered on the upper side with a mesh support. The lensis exposed to an atmosphere of humidified 2.1% O₂. The oxygen thatdiffuses through the lens is measured by the sensor. Lenses are eitherstacked on top of each other to increase the thickness or a thicker lensis used. The L/Dk of 4 samples with significantly different thicknessvalues are measured and plotted against the thickness. The inverse ofthe regressed slope is the Dk of the sample. The reference values arethose measured on commercially available contact lenses using thismethod. Balafilcon A lenses available from Bausch & Lomb give ameasurement of approx. 79 barrer. Etafilcon lenses give a measurement of20 to 25 barrer. (1 barrer=10⁻¹⁰ (cm³ of gas×cm²)/(cm³ of polymer×sec×cmHg)).

Uptake (Lysozyme, Lipocalin, Mucin)

Lysozyme uptake was measured as follows: The lysozyme solution used forthe lysozyme uptake testing contained lysozyme from chicken egg white(Sigma, L7651) solubilized at a concentration of 2 mg/ml in phosphatesaline buffer supplemented by Sodium bicarbonate at 1.37 g/l andD-Glucose at 0.1 g/l.

Three lenses for each example were tested using each protein solution,and three were tested using PBS (phosphate buffered saline) as a controlsolution. The test lenses were blotted on sterile gauze to removepacking solution and aseptically transferred, using sterile forceps,into sterile, 24 well cell culture plates (one lens per well) each wellcontaining 2 ml of lysozyme solution. Each lens was fully immersed inthe solution. 2 ml of the lysozyme solution was placed in a well withouta contact lens as a control.

The plates containing the lenses and the control plates containing onlyprotein solution and the lenses in the PBS, were parafilmed to preventevaporation and dehydration, placed onto an orbital shaker and incubatedat 35° C., with agitation at 100 rpm for 72 hours. After the 72 hourincubation period the lenses were rinsed 3 to 5 times by dipping lensesinto three (3) separate vials containing approximately 200 ml volume ofPBS. The lenses were blotted on a paper towel to remove excess PBSsolution and transferred into sterile conical tubes (1 lens per tube),each tube containing a volume of PBS determined based upon an estimateof lysozyme uptake expected based upon on each lens composition. Thelysozyme concentration in each tube to be tested needs to be within thealbumin standards range as described by the manufacturer (0.05 microgramto 30 micrograms). Samples known to uptake a level of lysozyme lowerthan 100 μg per lens were diluted 5 times. Samples known to uptakelevels of lysozyme higher than 500 μg per lens (such as etafilcon Alenses) are diluted 20 times.

1 ml aliquot of PBS was used for all samples other than etafilcon. 20 mlwere used for etafilcon A lens. Each control lens was identicallyprocessed, except that the well plates contained PBS instead of lysozymesolution.

Lysozyme uptake was determined using on-lens bicinchoninic acid methodusing QP-BCA kit (Sigma, QP-BCA) following the procedure described bythe manufacturer (the standards prep is described in the kit) and iscalculated by subtracting the optical density measured on PBS soakedlenses (background) from the optical density determined on lenses soakedin lysozyme solution.

Optical density was measured using a SynergyII Micro-plate readercapable for reading optical density at 562 nm.

Lipocalin uptake was measured using the following solution and method.The lipocalin solution contained B Lactoglobulin (Lipocalin) from bovinemilk (Sigma, L3908) solubilized at a concentration of 2 mg/ml inphosphate saline buffer (Sigma, D8662) supplemented by sodiumbicarbonate at 1.37 g/l and D-Glucose at 0.1 g/l.

Three lenses for each example were tested using the lipocalin solution,and three were tested using PBS as a control solution. The test lenseswere blotted on sterile gauze to remove packing solution and asepticallytransferred, using sterile forceps, into sterile, 24 well cell cultureplates (one lens per well) each well containing 2 ml of lipocalinsolution. Each lens was fully immersed in the solution. Control lenseswere prepared using PBS as soak solution instead of lipocalin. Theplates containing the lenses immersed in lipocalin solution as well asplates containing control lenses immersed in PBS, were parafilmed toprevent evaporation and dehydration, placed onto an orbital shaker andincubated at 35° C., with agitation at 100 rpm for 72 hours. After the72 hour incubation period the lenses were rinsed 3 to 5 times by dippinglenses into three (3) separate vials containing approximately 200 mlvolume of PBS. The lenses were blotted on a paper towel to remove excessPBS solution and transferred into sterile 24 well plates each wellcontaining 1 ml of PBS solution.

Lipocalin uptake was determined using on-lens bicinchoninic acid methodusing QP-BCA kit (Sigma, QP-BCA) following the procedure described bythe manufacturer (the standards prep is described in the kit) and iscalculated by subtracting the optical density measured on PBS soakedlenses (background) from the optical density determined on lenses soakedin lipocalin solution. Optical density was measured using a SynergyIIMicro-plate reader capable for reading optical density at 562 nm.

Mucin uptake was measured using the following solution and method. TheMucin solution contained Mucins from bovine submaxillary glands (Sigma,M3895-type 1-S) solubilized at a concentration of 2 mg/ml in phosphatesaline buffer (Sigma, D8662) supplemented by sodium bicarbonate at 1.37g/l and D-Glucose at 0.1 g/l.

Three lenses for each example were tested using Mucin solution, andthree were tested using PBS as a control solution. The test lenses wereblotted on sterile gauze to remove packing solution and asepticallytransferred, using sterile forceps, into sterile, 24 well cell cultureplates (one lens per well) each well containing 2 ml of Mucin solution.Each lens was fully immersed in the solution. Control lenses wereprepared using PBS as soak solution instead of lipocalin.

The plates containing the lenses immersed in Mucin as well as platescontaining control lenses immersed in PBS were parafilmed to preventevaporation and dehydration, placed onto an orbital shaker and incubatedat 35° C., with agitation at 100 rpm for 72 hours. After the 72 hourincubation period the lenses were rinsed 3 to 5 times by dipping lensesinto three (3) separate vials containing approximately 200 ml volume ofPBS. The lenses were blotted on a paper towel to remove excess PBSsolution and transferred into sterile 24 well plates each wellcontaining 1 ml of PBS solution.

Mucin uptake was determined using on-lens bicinchoninic acid methodusing QP-BCA kit (Sigma, QP-BCA) following the procedure described bythe manufacturer (the standards prep is described in the kit) and iscalculated by subtracting the optical density measured on PBS soakedlenses (background) from the optical density determined on lenses soakedin Mucin solution. Optical density was measured using a SynergyIIMicro-plate reader capable for reading optical density at 562 nm.

The kinetic half lives for components may be determined as follows. Thecomponents for each kinetics example were weighed into a 20 mL amberborosilicate glass scintillation vial (Wheaton 320 brand; Catalogue#80076-576, or equivalent). Vials were capped (using PTFE lined greencap, Qorpak; Supplier #5205/100, Catalogue #16161-213) and rolled on jarroller until all solids were dissolved and a homogeneous mixtures wereobtained.

Degas

Reactive monomer mixes were degassed under vacuum, under yellow lightfor 7-10 minutes, and back-filling with nitrogen after breaking vacuum.Vials were quickly capped and placed in compartment 1 of a twocompartment nitrogen cure box, via the gated aperature, 7, as shown inFIG. 2. The conditions in compartment 1 were room temperature and <0.5%oxygen (using continuous nitrogen purge).

Nitrogen Cure Box—Compartment 2

The oxygen level in both compartments was maintained bycontinuous/constant nitrogen purge. The temperature in Compartment 2 wasmaintained by a heater (COY, Laboratory Products Inc.). The nitrogencure box was allowed to equilibrate for a minimum of 4 hours prior toperforming each kinetics study. The degassed reactive mixture (intightly capped amber vial) was placed in compartment 1 during theequilibration period.

Light Source and Intensity Setting

As depicted in FIG. 3, 2 fluorescent light fixtures (Lithonia LightingFluorescent Luminaire (Gas Tube Luminaire), 60 cm×10.5 cm) each equippedwith 2 fluorescent lamps (Philips TLK 40 W/03, 58 cm) were arranged inparallel. The cure intensity was attenuated by adjusting the height ofthe shelf (shown in FIGS. 2 and 3) relative to the light source. Theintensity at a given shelf height was measured by placing the sensor ofa calibrated radiometer/photometer on the mirrored surface, consistentwith the position of the sample, as shown in FIG. 3. The sensor wasplaced directly under the space between the 2^(nd) and 3^(rd) lamps inthe 4 lamps arrangement.

Using a calibrated analytical balance (4 decimal places) the weight of aclear borosilicate glass scintillation vial (Wheaton 986541) with cap(white cap with polyethylene insert) was determined. The vial with capwas transferred to Compartment 1 of the Nitrogen Cure Box. The cap wasunscrewed and using a calibrated 10-100 μL Eppendorf Pipet, 100 μL ofthe Reactive Monomer Mixture was transferred into the vial. The vial wastightly capped, quickly moved into Compartment 2, via door 6, and placedon the mirrored surface 4, as shown in FIG. 2. The sample was placeddirectly under the space between the 2^(nd) and 3^(rd) lamps in the 4lamps arrangement. The light source 3, was turned on and the sample wasexposed for a specified time period. Although the light source was setat 4-5 mW/cm², the actual intensity reaching the sample is 0.7-1.3mW/cm², due the cap on the sample glass vials. After exposure, the lightsource 3, was turned off and the vial (with cap) was re-weighed todetermine the sample weight by difference. Using a calibrated 500-5000μL Eppendorf Pipet, 10 mL HPLC grade methanol was added to the vial.

Aliquots (100 μL) of the Reactive Monomer Mixture were pipetted intoseparate borosilicate glass scintillation vials and the above proceduredescribed above was performed to generate samples at the followingminimum time points (minutes): 0, 0.25, 0.50, 0.75, 1, 2, 4, 6, 8, 10.

Cured polymers were extracted in methanol overnight by gently shaking atroom temperature.

Extracts were analyzed for residual components by High PerformanceLiquid Chromatography with UV detection (HPLC/UV) using the followingprocedures.

Quantitation of the mPDMS in the extracts was performed against externalcalibration standards (about 6-11, using the response of the n=6oligomer), typically covering the range of 1 μg/mL-800 μg/mL. If theconcentrations of mPDMS in the extracts were outside the calibrationrange, the extracts were diluted with methanol to render concentrationswithin the calibration range for more accurate quantitation.

Chromatographic Conditions

Column: Agilent Zorbax Eclipse XDB18, 4.6×50 mm×1.8 μm

Column Temperature: 30° C.

UV Detector: 217 nm

Injection Volume: 20 μL

Mobile Phase

Eluent A: De-ionized

Eluent B: Acetonitrile

Eluent C: Isopropanol

Flow Rate: 1 mL/min

Time (mins) % A % B % C 0.0 50 48 2 0.5 50 48 2 2.0 0 60 40 5.0 0 60 405.1 0 30 70 8.0 0 30 70 8.1 50 48 2 10.0 50 48 2Quantitation of the components in the extracts other than mPDMS wasperformed against external calibration standards (about 6-11) for eachcomponent, typically covering the range of 1 μg/mL-800 μg/mL. If theconcentrations of components in the extracts were outside thecalibration range, the extracts were appropriately diluted with methanolto render concentrations within the calibration range for more accuratequantitation.Chromatographic ConditionsColumn: Agilent Zorbax Eclipse Plus 18, 4.6×75 mm×1.8 μmColumn Temperature: 30° C.UV Detector: 217 nmInjection Volume: 5 μLMobile PhaseEluent A: De-ionized water with 0.05% H₃PO₄Eluent B: Acetonitrile with 0.05% H₃PO₄Eluent C: MethanolFlow Rate: 1 mL/min

Time (mins) % A % B % C 0 95 5 0 5 95 5 0 15 0 100 0 23 0 100 0 24 0 3070 28 0 30 70 29 95 5 0 35 95 5 0Calculations1. At each time point the following values are determined:The concentration (ng/mL) of each component in the sample extract.The concentration of each component in the sample extract, expressed asa percent of the sample weight as follows:% Component=[(μg/mL*Volume of Extract*Dilution Factor*10⁻⁶ g/μg)/(gSample Weight)]*100The percent unreacted component present, expressed as a percent relativeto T₀ (where T₀ represented 100% unreacted component)% at T _(x)=(% Measured at T _(x)/% Measured at T ₀)*100

-   -   2. Using the % Component calculated above, the concentration of        each component in μmoles/g, is calculated as follows:        μmoles/g=(% Component*10³)/(Molecular Weight of Component)    -   3. Using the concentration of each component determined in        μmoles/g in step 2, the concentration at Time_(x) was expressed        as        Log [A _(x) ]/[A _(o)],        where [A_(x)] is the concentration of component A at x minutes        and [A_(o)] is the concentration of component A at 0 minutes        (T₀)

The expression Log [A_(x)]/[A₀] was determined for each time point.

First order kinetics were assumed for determining both thepolymerization kinetics rate and half life for each component. Thefollowing equations were used for calculating polymerization rateLog [A]/[A ₀ ]=−kt/2.303and half lifeln [A ₀]/[0.5A ₀ ]=kt _(1/2) or t _(1/2)=0.693/kFor each component, a plot of Log [A_(x)]/[A₀] versus time (minutes) wasgenerated. Typically, the data points (x, y) that best correspond tolinear growth (shorter cure times) were plotted and the data were fittedto a linear equation.

Using the slope, the kinetic rate constant (k) of each component wasevaluated from the following equation:k(minute⁻¹)=Slope*−2.303

The half-life (minutes) of each component was evaluated from thefollowing equation:t _(1/2)=0.693/k

The evaluated half-life for each component was compared to the datagenerated for the percent of each component relative to T₀, at each timepoint. Typically for each component, the time taken to attain 50%consumption was close to the half-life based on 1^(st) order kinetics Incases where the two were significantly different (typically about 30%for half-life of less than about 1 minute, 25% for half-life less thanabout 2.5 minutes but greater than 1 minute and 20% for half-lifegreater than 2.5 minutes), the data points (x, y) were re-evaluated togenerate kinetic rate constants (k) which would provide half-lives(based on 1^(st) order considerations) more consistent (within 20%) withthe measured values.

The Examples below further describe this invention, but do not limit theinvention. They are meant only to suggest a method of practicing theinvention. Those knowledgeable in the field of contact lenses as well asother specialties may find other methods of practicing the invention.However, those methods are deemed to be within the scope of thisinvention.

Some of the other materials that are employed in the Examples areidentified as follows:

EXAMPLES

The following abbreviations are used in the examples below:

-   FC Front mold curves-   BC Back mold curves-   NVP N-vinylpyrrolidone-   SiMAA 3-(methacryloxy-2-hydroxypropoxy)    propylbis(trimethylsiloxy)methyl silane,-   DMA N,N-dimethylacrylamide-   EGVE ethylene glycol vinyl ether-   HEMA 2-hydroxyethyl methacrylate-   HEAA hydroxyethylacrylamide-   mPDMS 800-1000 MW (M_(n)) monomethacryloxypropyl terminated    mono-n-butyl terminated polydimethylsiloxane-   OH-mPDMS    α-(2-hydroxy-1-methacryloxypropyloxypropyl)-ω-butyl-decamethylpentasiloxane,    (MW 612 g/mol), prepared as in Example 8 of US20100249356 A1-   Norbloc 2-(2′-hydroxy-5-methacrylyloxyethylphenyl)-2H-benzotriazole-   D3O 3,7-dimethyl-3-octanol-   TEGDMA tetraethyleneglycol dimethacrylate-   TRIS 3-methacryloxypropyltris(trimethylsiloxy)silane-   acPDMS bis-3-methacryloxy-2-hydroxypropyloxypropyl    polydimethylsiloxane (MW about 1000 g/mole)-   CGI 819 bis(2,4,6-trimethylbenzoyl)-phenylphosphineoxide-   EtOAc ethyl acetate-   DA decanoic acid-   Macromer A Described in Example 25 of U.S. Pat. No. 6,943,203-   GMMA 2,3-dihydroxypropyl methacrylate-   TAA t-amyl alcohol-   ETOH ethanol-   SA-2 N-(2,3-dihydroxypropane)-N′-(propyl    tetra(dimethylsiloxy)dimethylbutylsilane)acrylamide, as shown in    Formula XI

-   VMA N-vinyl-N-methyl acetamide

Examples 1-5

Reaction mixtures were formed by mixing the components listed in Table 1and degassed by applying vacuum at ambient temperature for about 17(±3)minutes. The reaction mixtures (75 μL) were then dosed at roomtemperature and <0.5% O₂, into thermoplastic contact lens molds(FC—Zeonor, BC Polypropylene) which had been degassed in N₂ box at RT(Compartment 1, FIG. 1) for a minimum of 12 hours prior to dosing. TheBC was placed on the FC mold to produce 8 BC/FC assemblies in a pallet.Eight pallets were assembled and moved into the cure compartment(Compartment 2, FIG. 1). The mold assembly was placed on a mirroredsurface, and a quartz plate (0.50 mm thick) was placed on top of the BCmold. The lenses were cured for 18 minutes, at an intensity of 4-5mW/cm², <0.5% O₂, and 50-55° C.

The lens molds were separated. The lenses remained in the front curvemold and were demolded dry via striking the underside of the FC mold.

Lenses were extracted in DI water (64 lenses in 500 mL) in a glass jarat ambient temperature for 90 minutes, with rolling. The lenses were“stored in borate buffered packing solution in lens vials and sterilizedat 122° C. for 30 minutes.

TABLE 1 1 2 3 4 5 mPDMS 0.00 5.00 10.00 15.00 20.00 1000 OH- 40.00 35.0030.00 25.00 20.00 mPDMS, n = 4 NVP 45.50 45.50 45.50 45.50 45.50 HEMA10.75 10.75 10.75 10.75 10.75 TEGDMA 1.50 1.50 1.50 1.50 1.50 Norbloc2.00 2.00 2.00 2.00 2.00 CGI 819 0.25 0.25 0.25 0.25 0.25[mPDMS]:HOmPDMS¹ 0 0.0087 0.2 0.37 0.61 ¹molar ratio

The blend of Example 5 was slightly hazy, indicating slightinhomogeneity of the reaction mixture. The properties of the lenses ofExamples 1 and 4 are shown in Table 2, below.

TABLE 2 Mechanicals Ex.# % H₂O % Haze DCA Mod. (psi) Elong. (%) Dk 148.1 (0.1)  9 (1) 63 (5) 195.0 (12.0) 111.8 (23.1) 70 4 47.8 (0.1) 17(1) 59 (4) 178.4 (17.8) 110.6 (25.0) 82

The lenses from Example 1 were brittle and some lenses shattered orcracked during the mechanical release from the lens mold. The level ofobserved brittleness decreased, and demolding and handling of the drylenses increased as the concentration of mPDMS increased. Example 4,which contained 15 wt % mPDMS, and molar ratio of mPDMS:HOmPDMS of 0.37displayed good release and demolding. The lenses of Example 4 alsodisplayed desirable water content, haze and Dk.

Examples 6-10

Lenses were made using the procedure described in Examples 1-5, but theformulations shown in Table 3.

TABLE 3 Ex # 6 7 8 9 10 mPDMS 15 15 15 15 15 1000 OH- 25 25 25 25 0mPDMS, n = 4 SiMAA 0 0 0 0 25 NVP 46 46.25 46.50 46.75 46.50 HEMA 10.7510.75 10.75 10.75 10.75 TEGDMA 1 0.75 0.50 0.25 0.50 Norbloc 2 2 2 2 2CGI 819 0.25 0.25 0.25 0.25 0.25

TABLE 4 Mechanicals % Mod. Elong. Ex [TEGDMA] % H₂O Haze DCA (psi) (%)Dk 6 1 NT NT NT NT NT NT 7 0.75 53.8 (0.2) 6 57 129.1 198.3 82 (1) (2)(6.5) (40.1) 8 0.5 54.7 (0.2) 8 58 97.6 244.7 82 (1) (8) (9.7) (65.1) 90.25 59.0 (0.0) 36 NT 78.8 259.7 85 (1) (3.4) (36.8) 10 0.5 52.1 (0.2) 776 172.6 171.4 54 (1) (2) (15.4) (39.1) 11 0.5 52.8 (0.1) 7 67 159.1168.4 54 (1) (2) (13.9) (48.0)

All lenses were clear, as shown by the low haze values, and feltlubricious when hydrated. The lenses from Example 10 were brittle andsome shattered and cracked upon demolding. The lenses of Examples 8 and9 displayed moduli below about 100 psi, which is desirable in softcontact lens applications. The series of Examples 6-11 shows thatcrosslinker concentrations up to about 0.8 wt % (1.8 mmole per 100 greactive components), and in some embodiments between about 0.2 andabout 0.6 wt % (0.6 to 2.4 mmole per 100 g reactive components) providedesirable moduli.

Example 11

Lenses were made as in Example 10, and extracted using the followingisopropanol “step down” into PS:

25/75 iPA/H₂O (10 mins), H₂O (30 mins), H₂O (10 mins), H₂O (10 mins),

The properties are shown in Table 4, above.

Examples 12-16

Contact lenses were made from the formulations in Table 5, using theprocedure described in Examples 1-5.

TABLE 5 Ex# 12 13 14 15 16 Wt % mPDMS 15.00 15.00 15.00 15.00 15.00 1000OH- 25.00 25.00 25.00 25.00 25.00 mPDMS, n = 4 NVP 57.25 54.50 52.5050.50 46.50 HEMA 0.00 2.75 4.75 6.75 10.75 TEGDMA 0.50 0.50 0.50 0.500.50 Norbloc 2.00 2.00 2.00 2.00 2.00 CGI 819 0.25 0.25 0.25 0.25 0.25

The lenses of Example 12 were difficult to mechanically release from themold and became hazy in packing solution. The properties of the lensesof Example 12 were not measured. The properties of the lenses ofExamples 13-16 were measured and are reported in Table 6.

TABLE 6 Mechanicals % % HEMA: % % Mod. Elong. Ex# HEMA NVP NVP H₂O HazeDCA (psi) (%) Dk 13 2.75 54.50 0.043 63.0 57 69 77.7 157.7 87 (0.3) (5)(10) (3.7) (37.6) 14 4.75 52.50 0.077 60.0 35 71 86.3 194.9 83 (0.5) (1)(16) (5.2) (63.1) 15 6.75 50.50 0.114 57.4 9 49 93.1 219.7 86 (0.4) (0)(5) (5.8) (50.0) 16 10.75 46.50 0.197 54.7 8 58 97.6 244.7 82 (0.2) (1)(8) (9.7) (65.1)

Examples 12-16 show that increasing levels of hydroxylalkylmethacrylates, such as HEMA in the zero diluent formulations decreasehaze levels, decrease distortions in the resulting lenses and improvemechanical release from the molds.

The HO:Si ratio (including both HEMA and HO-mPDMS) for Example 12 was0.11, while the ratios for Examples 13-16 ranged from 0.17 (Example 13)to 0.33 (Example 16).

Examples 17-19

Contact lenses were made from the formulations in Table 7, using theprocedure described in Examples 1-5. The properties were measured andare reported in Table 8.

TABLE 7 Wt % Ex# Component 17 18 19 % Si 8.89 9 11.5 HO:Si¹ 0.39 0.370.24 mPDMS 1000 10 12.75 16.75 OH-mPDMS, 25 21.75 27.5 n = 4 NVP 51.5 5246.5 HEMA 10.75 10.75 6.75 TEGDMA 0.5 0.5 0.5 Norbloc 2 2 2 CGI 819 0.250.25 0.25 HO:Si = all hydroxyl in RMM

TABLE 8 % Mechanicals Ex. # % H₂O Haze DCA Mod. (psi) Elong. (%) Dk 1760.3 (0.1) 6 (1) 50 (4)  89 (6) 213 (40) 60 18 59.3 (0.2) 7 (0) 63 (14)88 (5) 171 (46) 65 19 53.4 (0.1) 13 (1)  67 (16) 118 (6)  188 (67) 98

The lenses of Example 17 displayed a good balance of properties, butwere brittle upon mechanical release. About 25% of the lenses displayedfractures upon hydration, and some lenses remained on the back curvemold upon mechanical release.

The lenses of Examples 18 and 19, had increased concentrations of mPDMSand Si content. These lenses displayed excellent mechanical release,with no fractures observed in the hydrated lenses and a desirablebalance of lens properties. The lenses of Example 19 displayed a Dk of98 and a water content of greater than 50%.

Comparative Example 1 and Examples 20-27

Lenses were made from the formulations of Table 9, using the proceduredescribed in Examples 1 through 5. The properties were measured and areshown in Table 10. Biometric data (lipocalin, mucin, lysozyme uptake andlysozyme activity) were also measured and are shown in Table 11.

TABLE 9 Comp Wt % Ex.# 20 21 22 23 24 25 26 27 28 % Si 7.1 8 9 10.5 11.59 10.5 9.2 11.5 mPDMS 1000 9.35 11.5 12.75 15 16.50 12.75 15 0 16.5OH-mPDMS, n = 4 18 19 21.75 25 27.50 21.75 25 40 27.5 NVP 63.15 60 56.0050.5 46.5 56 50.5 50.88 46.5 GMMA 0 0 0 0 0 6.73 6.73 6.62 6.73 HEMA6.73 6.73 6.73 6.73 6.73 0 0 0 0 Blue 0.02 0.02 0.02 0.02 0.02 0.02 0.020 0.02 HEMA TEGDMA 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.25 0.5 Norbloc 2 2 2 22 2 2 2 2 CGI 819 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25

TABLE 10 % Sessile Mechanicals Ex # %[Si]; HMA % H₂O Haze RI DCA DropMod. (psi) Elong. (%) Dk 20  7.1; HEMA 68.5 (0.1)  5 (0) NT 36 (9) 44(3)   65 (5) 260 (47) 59.2 21  8.0; HEMA 63.2 (0.3)  8 (1) 1.3925 38 (8)39 (3)   76 (5) 215 (53) 61.3 22  9.0; HEMA 61.3 (0.1)  9 (1) 1.3927 43(10) 39 (2)   83 (9) 244 (35) 76.2 23 10.5; HEMA 56.9 (0.2)  6 (1)1.4012 38 (9) 39 (3)   100 (9) 249 (59) 88.4 24 11.5; HEMA 53.7 (0.2)  7(1) NT 60 (6) 63 (6)   112 (5) 224 (31) 103.7 25  9.0; GMMA 61.8 (0.1) 4 (1) 1.3960 44 (8) 46 (4)   93 (6) 246 (38) 73.5 26 10.5; GMMA 57.3(0.0)  3 (0) 1.4015 56 (16) 42 (4)   100 (7) 212 (50) 81.8 27  9.2; GMMA58.5 (0) 10 (3) NT 39 (5) NT   120 (6) 184 (22) 61.2 28 11.5: GMMA 54.3(0.2)  8 (0) NT 91 (12) NT 104.1 (5.9) 216 (36.7) 90.7

TABLE 12 %[Si]; Hydro- Lipocalin Mucin Lysozyme % Active Ex. # phile(μg/Lens) (μg/Lens) (μg/Lens) Lysozyme 21 8.0; 3.75 (0.06) 5.02 (0.04)5.61 (0.05) 81 (4) HEMA 22 9.0; 4.15 (0.16) 5.44 (0.10) 6.45 (0.04) 81(3) HEMA 25 9.0; 3.79 (0.13) 4.92 (0.15) 6.15 (0.20) 82 (6) GMMA 2310.5;  3.76 (0.57) 5.13 (0.16) 6.39 (0.06) 81 (7) HEMA 26 10.5;  3.54(0.28) 4.85 (0.10) 5.81 (0.27) 77 (6) GMMA

All lenses in Examples 21 through 26 displayed a desirable balance oflens properties and uptake characteristics.

Lenses of Example 27 were hard and brittle after curing and shatteredduring mechanical dry release. However, lenses of Example 27 werereleased successfully using 70/30 IPA/water.

Examples 29-33

Lenses were made from the formulations of Table 13, using the proceduredescribed in Examples 1 through 5. The properties were measured and areshown in Table 14.

TABLE 13 Wt % Ex# 29 30 31 32 33 % Si 7.32 8.47 9.62 10.77 11.92 mPDMS5.00 5.00 5.00 5.00 5.00 1000 OH-, 25.00 30.00 35.00 40.00 45.00 mPDMS n= 4 PVP K90 7.00 7.00 7.00 7.00 7.00 NVP 49.50 44.50 39.50 34.50 29.50HEMA 10.75 10.75 10.75 10.75 10.75 TEGDMA 0.50 0.50 0.50 0.50 0.50Norbloc 2.00 2.00 2.00 2.00 2.00 CGI 819 0.25 0.25 0.25 0.25 0.25

TABLE 14 % Mechanicals Ex# % H₂O Haze DCA Mod. (psi) Elong. (%) Dk 2965.2 (0.2) 5 (0)  63 (6)  72 (6) 227 (61) 56 30 60.5 (0.2) 6 (0)  58 (6)102 (7) 242 (33) 60 31 57.0 (0.1) 7 (1)  81 (10) 100 (7) 260 (27) 77 3253.0 (0.5) 6 (0) 100 (5) 117 (9) 255 (27) 86 33 48.9 (0.0) 5 (1) 101 (8) 149 (17) 250 (53) 94

The lenses of Examples 29 and 30 display a desirable balance ofproperties. As the concentration of NVP in the formulations drops belowabout 40 wt %, the advancing contact angle (DCA) increases above 80° C.,which is undesirable for a contact lens without a surface treatment orcoating. This is surprising as all the formulations contain 5 wt % PVP(K90) which has been shown to dramatically improve the wettability ofcontact lenses made from formulations without PVP. In this series, theconcentration of HO-mPDMS was also increased from 25 wt % in Example 29to 45 wt % in Example 33. Examples 32 displays a modulus of 117 psi,which is marginally acceptable for some contact lenses and could beadjusted by decreasing the crosslinker content. Example 33 displays amodulus of 149 psi which is undesirably high, but could be decreased bylowering the crosslinker concentration as in Example 28.

Examples 34-39

Lenses were made from the formulations of Table 15, using the proceduredescribed in Examples 1 through 5. The properties were measured and areshown in Table 16.

TABLE 15 Component Wt % Ex# 34 35 36 37 38 39 mPDMS 10 7 7 7 10 10 1000OH- 25 25 30 35 32 35 mPDMS, n = 4 PVP K30 7 7 7 7 7 7 NVP 45.25 48.2543.25 38.25 38.25 35.25 HEMA 10 10 10 10 10 10 TEGDMA 0.5 0.5 0.5 0.50.5 0.5 Norblock 2 2 2 2 2 2 CGI 819 0.25 0.25 0.25 0.25 0.25 0.25

TABLE 16 % % Mechanicals Ex# H₂O Haze DCA Mod. (psi) Elong. (%) Dk 3461.7 (0.2)  6 (1)  68 (13) 86 (4) 229 (41) 61 36 58.6 (0.1)  8 (0)  75(11)  99 (10) 251 (40) 78 37 55.3 (0.0) 10 (1) 105 (6) 111 (14) 248 (34)88 38 56.1 (0.4) 13 (1) 102 (6) 99 (8) 248 (56) 86 39 53.3 (0.0) 14 (1)120 (5) 119 (14) 235 (39) 95

Similar to Examples-33, formulations which contained less than about 40wt % NVP did not display advancing contact angles less than about 80° C.Also, considering Examples 37 and 39, concentrations of HO-mPDMS greaterthan about 32 wt % displayed moduli which may be higher than desirablein some cases. These moduli could be decreased by decreasing thecrosslinker concentration, decreasing the HO-mPDMS concentration or acombination.

Examples 40-43 and Comparative Examples 1 and 2

Contact lenses were made from the Formulations of listed in Table 17.3using the method described in Examples 1-5. The properties of the lenseswere measured and are shown in Table 18, below.

TABLE 17 Comp. Ex. 40 Ex. 41 CE1 CE2 Ex. 42 Ex. 43 OH- 40 40 40 40 0 0mPDMS SA2 0 0 0 0 41 40 NVP 50.5 50.5 0 0 51.5 50.5 DMA 0 0 50.5 50.5 00 HEMA 6.75 8.75 6.75 8.75 6.75 6.75 TEGDMA 0.5 0.5 0.5 0.5 0.5 0.5Norbloc 2 0 2 0 0 2 CGI 819 0.25 0.25 0.25 0.25 0.25 0.25

TABLE 18 % Mechanicals Ex. # % H₂O Haze DCA Mod. (psi) Elong. (%) Dk 4058.4 (0.2)  4 (0)  44 (4) 103 (11) 220 (36) 75 41 66.6 (0.1) 24 (1)  50(3) 63 (8) 192 (76) 79 CE1 59.8 (0.1)  5 (1) 127 (14) 54 (7) 227 (52) 49CE2 58.1 (0.2)  3 (1) 132 (7) 78 (7) 199 (39) 49 42   67 (0.2) 67 (2) 51 (3) 64 (7) 229 (97) 82 43 65.5 (0.1)  8 (1)  68 (7) 105 (9)  242(49) 57

The lenses of Examples 40 through 43 show desirable haze andwettability, as well as a balance of other desirable properties.Examples 42 and 43 were made using SA2, a methacrylamidesilicone-containing component. Each of these Examples had ratios of theslow-reacting hydrophilic monomer half life:silicone-containingcomponent half life greater than about 2. Comparative Examples 1 and 2used DMA instead of NVP, and did not display desirable contact angles.

Comparing the modulii of Comparative Example 2 (54 psi, with Norbloc)and Comparative Example 3 (78 psi without Norbloc) it can be seen thatthe change in the reactivity rate for TEGDMA caused by the inclusion ofNorbloc was sufficient to decrease crosslinking in the network of theresulting polymer. Thus, in additional to changing the amount ofcrosslinker, one can also choose a crosslinker with a differentreactivity ratio to achieve a desired polymer structure and modulus. Thesame behavior is also observed comparing the SA2/NVP-containingformulations of Examples 42 and 43.

Examples 44-49

Lenses were made using the formulations shown in Table 84. The reactionmixtures were degassed by applying vacuum at ambient temperature forabout 17(±3) minutes. The reaction mixture (75 μL) was then dosed atroom temperature and <0.1% O₂, into thermoplastic contact lens molds(FC—Zeonor, BC Polypropylene) which had been degassed in N₂ box at RT(Compartment 1, FIG. 1) for a minimum of 12 hours prior to dosing. TheBC was placed on the FC mold and the lenses were moved into Compartment2 and cured for 20 minutes, at an intensity of 4-5 mW/cm², <0.1% O₂, and62-65° C.

The molds for all the lenses were mechanically separated and the lensesremained in the FC. The lenses were dry released by pressing on the backof the front curve. Lenses were extracted in DI water

All lenses were stored in borate buffered packing solution in lens vialsand sterilized at 122° C. for 30 minutes.

Lens properties were measured and are shown in Table 20.

TABLE 19 Ex.# 44 45 46 47 48 49 mPDMS 19.35 19.35 19.35 19.35 19.3519.35 1000 OH- 27.50 27.50 27.50 27.50 27.50 27.50 mPDMS (n = 4) VMA0.00 8.00 12.00 22.00 32.00 44.00 HEMA 6.50 6.50 6.50 6.50 6.50 6.50 NVP44.00 36.00 32.00 22.00 12.00 0.00 TEGDMA 0.20 0.20 0.20 0.20 0.20 0.20TAC 0.20 0.20 0.20 0.20 0.20 0.20 Norbloc 1.75 1.75 1.75 1.75 1.75 1.75CGI 819 0.50 0.50 0.50 0.50 0.50 0.50

TABLE 20 Mechanicals % % Mod. Elong. Res. Res. Lens H₂O Haze DCA (psi)(%) Dk NVP VMA 44 55 (0) 6 (0) 55 (3)  95 (6) 270 (34) 96 0.8 N/A (0.02)45 56 (0) 6 (0) 67 (5) 104 (7) 233 (49) 100 NT NT 46 56 (0) 5 (0) 58 (4)100 (8) 258 (36) 100 0.51 1.15 (0.02) (0.08) 47 58 (0) 6 (0) 56 (9)  91(9) 223 (54) 96 0.4 2.2 (0.04) (0.2) 48 58 (0) 7 (0) 56 (5)  92 (10) 260(62) 103 0.3 2.98 (0.01) (0.06) 49 58 (0) 13 (2)  50 (10)  86 (7) 262(54) 106 N/A 4.52 (0.61)Lenses having a desirable balance of properties were made fromformulations comprising VMA and mixtures of VMA and NVP.

What is claimed is:
 1. A silicone hydrogel comprising between about 8and about 17 wt % silicon, an advancing dynamic contact angle of lessthan about 80° without surface modification formed from a reactivemixture comprising at least one hydroxyl substituted, monofunctionalpolydialkylsiloxane monomer having between 2 and 120 dialkylsiloxanerepeating units; optionally one or more monofunctional siloxane monomerhaving 7 to 120 dialkylsiloxane repeating units, with the proviso thatif said monofunctional, hydroxyl-containing siloxane monomer has lessthan 4 dialkylsiloxane repeating units or is of Formula IX

X is O or NR₁₆; R₁₂ is H or methyl; R₁₅ is a C₁ to C₄ alkyl; Wherein pis 4-20, R₁₇ is independently a C₁ to C₄ alkyl which may be fluorinesubstituted, or phenyl, or trimethylsiloxy groups; R₁₈ is a divalentalkyl group substituted with at least one hydroxyl group; X is O orNR₁₆; and R₁₆ is selected from H, C₁₋₄ alkyl; at least onemonofunctional, siloxane monomer having 7 to 120 dialkylsiloxanerepeating units is included; about 40-about 60 wt % of at least one slowreacting hydrophilic monomer; at least one hydroxyl containinghydrophilic monomer, wherein the molar ratio of hydroxyl containingcomponents to the slow reacting hydrophilic monomer is between about0.15 to about 0.4, wherein the reactive mixture is free of diluent. 2.The silicone hydrogel of claim 1 comprising between about 8 to about 15wt % silicon.
 3. The silicone hydrogel of claim 1 wherein saidmonofunctional siloxane monomer comprises 7 to 60 dialkylsiloxanerepeating units.
 4. The silicone hydrogel of claim 1 wherein saidmonofunctional siloxane monomer comprises 7 to 30 dialkylsiloxanerepeating units.
 5. The silicone hydrogel of claim 1 wherein saidmonofunctional siloxane monomer comprises one or two hydroxyl groups. 6.The silicone hydrogel of claim 5 wherein said hydroxyl are located neareither a monofunctional reactive end or a terminal end.
 7. The siliconehydrogel of claim 1 wherein said silicone hydrogel comprises about 45 toabout 60 wt % hydroxyalkyl (meth)acrylate or (meth)acrylamide.
 8. Thesilicone hydrogel of claim 1 further comprising a Dk of at least about60.
 9. The silicone hydrogel of claim 1 further comprising a Dk of atleast about
 80. 10. The silicone hydrogel of claim 1 further comprisinga water content of at least about 55%.
 11. The silicone hydrogel ofclaim 1 further comprising a water content of at least about 60%. 12.The silicone hydrogel of claim 1 further comprising an advancing contactangle of less than about 80°.
 13. The silicone hydrogel of claim 1further comprising a % haze of less than about 50%.
 14. The siliconehydrogel of claim 1 further comprising a % haze of less than about 10%.15. The silicone hydrogel of claim 1 further comprising a modulus ofless than about 120 psi.
 16. The silicone hydrogel of claim 1 furthercomprising a modulus of about 100 psi or less.
 17. The silicone hydrogelof claim 1 wherein said slow-reacting hydrophilic monomer comprises areactive group selected from the group consisting of (meth)acrylamides,vinyls, allyls and combinations thereof.
 18. The silicone hydrogel ofclaim 1 wherein said slow-reacting hydrophilic monomer comprises areactive group selected from the group consisting of vinyls, allyls andcombinations thereof and said monofunctional polydialkylsiloxane monomerand said monofunctional, hydroxyl-containing siloxane monomer comprise areactive group selected from the group consisting of (meth)acrylates,styryls, amides and mixtures thereof.
 19. The silicone hydrogel of claim1 wherein said slow-reacting hydrophilic monomer comprises a reactivegroup selected from the group consisting of N-vinyl amides, O-vinylcarbamates, O-vinyl carbonates, N-vinyl carbamates, O-vinyl ethers,O-2-propenyl, wherein the vinyl or allyl groups may be furthersubstituted with a methyl group.
 20. The silicone hydrogel of claim 1wherein said slow reacting hydrophilic monomer comprises at least onehydrophilic group selected from the group consisting of hydroxyls,amines, ethers, amides, ammonium groups, carboxylic acid, carbamates andcombinations thereof.
 21. The silicone hydrogel of claim 1 wherein saidslow reacting hydrophilic monomer comprises at least one hydrophilicgroup selected from the group consisting of hydroxyls, ethers, amides,carboxylic acid combinations thereof.
 22. The silicone hydrogel of claim1 wherein said slow reacting hydrophilic monomer is selected fromN-vinylamide monomer of Formula I, a vinyl pyrrolidone of Formula II-IV,n-vinyl piperidone of Formula V:

wherein R is H or methyl; R₁, R₂, R₃, R₆, R₇, R₁₀, and R₁₁ areindependently selected from H, CH₃, CH₂CH₃, CH₂CH₂CH₃, C(CH₃)₂; R₄ andR₅ are independently selected from CH₂, CHCH₃ and C(CH₃); R₅ is selectedfrom H, methyl, ethyl; and R₉ is selected from CH═CH₂, CCH₃═CH₂, andCH═CHCH₃.
 23. The silicone hydrogel of claim 22 wherein theslow-reacting hydrophilic monomer is selected from the vinyl pyrrolidoneof Formula II or IV or the N-vinyl amide monomer of Formula I, and thetotal number of carbon atoms in R₁ and R₂ is 4 or less.
 24. The siliconehydrogel of claim 22 wherein the slow-reacting hydrophilic monomer isselected from a vinyl pyrrolidone of Formula III or IV and R₆ is methyl,R₇ is hydrogen, R₉ is CH═CH₂, R₁₀ and R₁₁ are H.
 25. The siliconehydrogel of claim 1 wherein the slow-reacting hydrophilic monomer isselected from ethylene glycol vinyl ether (EGVE), di(ethylene glycol)vinyl ether (DEGVE), N-vinyl pyrrolidone (NVP),1-methyl-3-methylene-2-pyrrolidone, 1-methyl-5-methylene-2-pyrrolidone,5-methyl-3-methylene-2-pyrrolidone; 1-ethyl-5-methylene-2-pyrrolidone,N-methyl-3-methylene-2-pyrrolidone, 5-ethyl-3-methylene-2-pyrrolidone,1-n-propyl-3-methylene-2-pyrrolidone,1-n-propyl-5-methylene-2-pyrrolidone,1-isopropyl-3-methylene-2-pyrrolidone,1-isopropyl-5-methylene-2-pyrrolidone, N-vinyl-N-methyl acetamide (VMA),N-vinyl-N-ethyl acetamide, N-vinyl-N-ethyl formamide, N-vinyl formamide,N-vinyl acetamide, N-vinyl isopropylamide, allyl alcohol, N-vinylcaprolactam, N-2-hydroxyethyl vinyl carbamate, N-carboxy-β-alanineN-vinyl ester; N-carboxyvinyl-β-alanine (VINAL),N-carboxyvinyl-α-alanine and mixtures thereof.
 26. The silicone hydrogelof claim 1 wherein the slow-reacting hydrophilic monomer is selectedfrom the group consisting of N-vinylpyrrolidone, N-vinylacetamide,1-methyl-3-methylene-2-pyrrolidone, 1-methyl-5-methylene-2-pyrrolidone,5-methyl-3-methylene-2-pyrrolidone, and mixtures thereof.
 27. Thesilicone hydrogel of claim 1 wherein the slow-reacting hydrophilicmonomer is selected from the group consisting of NVP, VMA and1-methyl-5-methylene-2-pyrrolidone.
 28. The silicone hydrogel of claim 1wherein the slow-reacting hydrophilic monomer comprises NVP.
 29. Thesilicone hydrogel of claim 1 wherein said hydroxyalkyl monomer isselected from hydroxyalkyl (meth)acrylate or (meth)acrylamide monomer ofFormula X or a styryl compound of Formula XI

wherein R₁ is H or methyl, X is O or NR₄, R₄ is a H, C₁ to C₄ alkyl,which may be further substituted with at least one OH, and R is selectedfrom C₂-C₄ mono or dihydroxy substituted alkyl, and poly(ethyleneglycol) having 1-10 repeating units.
 30. The silicone hydrogel of claim29 wherein R₁ is H or methyl, X is oxygen and R is selected from C₂-C₄mono or dihydroxy substituted alkyl, and poly(ethylene glycol) having1-10 repeating units.
 31. The silicone hydrogel of claim 29 wherein R₁methyl, X is oxygen and R is selected from C₂-C₄ mono or dihydroxysubstituted alkyl, and poly(ethylene glycol) having 2-20 repeatingunits.
 32. The silicone hydrogel of claim 1 wherein said hydroxyalkylmonomer is selected from the group consisting of 2-hydroxyethylmethacrylate, 2-hydroxyethyl acrylate, 3-hydroxypropyl (meth)acrylate,2-hydroxypropyl (meth)acrylate, 1-hydroxypropyl-2-(meth)acrylate,2-hydroxy-2-methyl-propyl (meth)acrylate, 3-hydroxy-2,2-dimethyl-propyl(meth)acrylate, 4-hydroxybutyl (meth)acrylate, glycerol (meth)acrylate,2-hydroxyethyl (meth)acrylamide, polyethyleneglycol monomethacrylate,bis-(2-hydroxyethyl) (meth)acrylamide, 2,3-dihydroxypropyl(meth)acrylamide, and mixtures thereof.
 33. The silicone hydrogel ofclaim 1 wherein said hydroxyalkyl monomer is selected from the groupconsisting of 2-hydroxyethyl methacrylate, glycerol methacrylate,2-hydroxypropyl methacrylate, hydroxybutyl methacrylate,3-hydroxy-2,2-dimethyl-propyl methacrylate, and mixtures thereof. 34.The silicone hydrogel of claim 1 wherein said hydroxyalkyl monomercomprises 2-hydroxyethyl methacrylate, 3-hydroxy-2,2-dimethyl-propylmethacrylate, glycerol methacrylate and mixtures comprising them. 35.The silicone hydrogel of claim 1 wherein said monofunctionalpolydialkylsiloxane monomer is selected from the group consisting ofmonomethacryloxypropyl terminated mono-n-butyl terminatedpolydimethylsiloxane, monomethacryloxypropyl terminated mono-n-methylterminated polydimethylsiloxane, monomethacryloxypropyl terminatedmono-n-butyl terminated polydiethylsiloxane, monomethacryloxypropylterminated mono-n-methyl terminated polydiethylsiloxane,N-(2,3-dihydroxypropane)-N′-(propyl tetra(dimethylsiloxy)dimethylbutylsilane)acrylamide,α-(2-hydroxy-1-methacryloxypropyloxypropyl)-ω-butyl-octamethylpentasiloxane,and mixtures thereof.
 36. The silicone hydrogel of claim 1 wherein saidmonofunctional polydialkylsiloxane monomer is selected from the groupconsisting of monomethacryloxypropyl terminated mono-n-butyl terminatedpolydimethylsiloxane, monomethacryloxypropyl terminated mono-n-methylterminated polydimethylsiloxane, N-(2,3-dihydroxypropane)-N′-(propyltetra(dimethylsiloxy) dimethylbutylsilane)acrylamide, and mixturesthereof.
 37. The silicone hydrogel of claim 1 further comprising atleast one crosslinking monomer.
 38. The silicone hydrogel of claim 37wherein said crosslinker is present in a molar concentration betweenabout 0.6 to about 2.4 mmole/100 g reactive components.
 39. The siliconehydrogel of claim 37 wherein said crosslinker is present in a molarconcentration between about 0.6 to about 1.8 mmole/100 g reactivecomponents.
 40. The silicone hydrogel of claim 1 further comprising atleast one photoinitiator.
 41. The silicone hydrogel of claim 1 whereinsaid reaction mixture further comprises at least one UV absorbingcompound.
 42. The silicone hydrogel of claim 41 wherein said at leastone UV absorbing compound is reactive.
 43. The silicone hydrogel ofclaim 41 comprising between about 1 wt % and about 2 wt % UV absorber.44. The silicone hydrogel of claim 37 wherein said reaction mixturefurther comprises at least one slow reacting crosslinker and at leastone fast reacting crosslinker.
 45. The silicone hydrogel of claim 44wherein said at least one slow reacting crosslinker and at least onefast reacting crosslinker are each present in said reaction mixture inamounts between about 0.05 to about 0.3 wt %.
 46. The silicone hydrogelof claim 44 wherein said at least one slow reacting crosslinker and atleast one fast reacting crosslinker are each present in said reactionmixture in amounts between about 0.1 to about 0.2 wt %.